There is conventionally known an air battery of the type disclosed in Japanese Patent No. 3735518. The air battery of Japanese Patent No. 3735518 has an electrode unit, in which a non-aqueous electrolyte layer is interposed between a cathode and an anode, accommodated together with terminals of the cathode and the anode in an accommodation casing such that both of the terminals protrude in opposite directions from the accommodation casing. In the air battery, a plurality of air holes are made in a cathode-side wall portion of the accommodation casing and closed with a seal tape. For use of the air battery, the seal tape is peeled off so as to open the air holes and provide a supply of air (oxygen) to the cathode.
In recent years, researches and developments have been made on air batteries as drive power sources or auxiliary power sources for vehicles e.g. automotive vehicles. It is required to, for use in a vehicle, form air batteries with a simple thin structure and constitute a battery pack by series connection of the air batteries in view of the output and capacity required for the vehicle and the narrow limited installation space in the vehicle etc. However, air batteries of the above conventional type cannot directly be connected to each other and are substantially impractical to use as vehicle power sources.
Further, the cathode layer is formed of a thin air-permeable material in the above conventional air battery. The mechanical strength of the cathode layer is thus lower than that of the metallic anode layer so that the cathode layer may be warped outwardly when electrolyte expansion occurs due to heat generation or oxide formation after the initiation of use of the air battery. It is thus likely that the conventional air battery will cause increase in internal resistance and decrease in air passage cross-sectional area and thereby decrease in output especially in the case where the air battery is reduced in thickness. It has been a challenge to solve these problems.